


running out of stamina

by orphan_account



Category: Supergirl (TV 2015)
Genre: Alpha/Beta/Omega Dynamics, F/F, G!P Kara
Language: English
Status: In-Progress
Published: 2020-10-30
Updated: 2020-11-12
Packaged: 2021-03-09 00:49:04
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,958
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27275971
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: Kara has one more secret to tell Lena. Once everything is out in the open, the couple will have to deal with more sensitive issues.ORKara is a virgin Alpha with stamina issues
Relationships: Kara Danvers/Lena Luthor
Comments: 25
Kudos: 487





	1. Chapter 1

**Author's Note:**

> My very first fic :)
> 
> I have no beta so pls go easy on me lol
> 
> READ THE TAGS

They’d been dating for three months. Three blissful months full of hand-holding, dates, cuddling on the couch during movie nights, and only getting to second base. Lena had no issue with this, more than happy to go at Kara’s pace. 

It was another movie night that resulted in the two women making out on the couch like hormonal teenagers when Kara pulled away. 

“You okay?” Lena puffed out, catching her breath. 

“Lena, I have to tell you something.” 

_Well, that sounded ominous._ Lena sat up slightly, gathering her bearings. “Kara, you can tell me anything.” She assured, rubbing her hand across Kara’s shoulder. 

“I know we said no more secrets, only honesty. But I’ve been keeping something from you.”

Lena’s brows furrow and Kara is quick to continue. “It’s something super personal, and only a handful of people know, and you being my girlfriend deserve to know, especially with us becoming more...intimate.” 

Lena could tell Kara was working herself up, whatever it was she was going to tell her making her nervous. “Kara, you can tell me anything, love.” 

Kara smiled slightly, “Well, as you know, I’m an alien.” 

“Yes, that has been established”

“So I have alien biology.”

“Right…”

Kara took a deep breath, “Kryptonians were classed three different ways. Alpha, beta, and omega, and depending on what someone presents as, it will determine their...ya know...genitals.” 

Lena’s eyes widened. _I don’t remember that bit of information in any of Lex’s files._

“What does that mean for you?”

“I presented as an alpha. Which means I have a penis. I can form a knot and I go into a rut about 4 times a year. During a rut is when I’m fertile.” Kara explains, cringing the whole way through. 

Lena’s mind is running a mile per minute at this new information, her scientific side wanting to ask about 50 different questions. She pushed those thoughts down though to let Kara know how she felt about all of this. 

“Kara, you know I love you right? Your biology isn’t going to change that.” 

“I’m also a virgin!” Kara blurts out, catching Lena completely off guard. 

“Oh..I- that’s okay! We can go at your pace Kara, there’s no rush. I love you and I want you to be comfortable.” Lena quickly said, pulling Kara into a hug. 

“Thank you, Lena. You don’t know how much it means to me for you to be so accepting.” 

“Of course I would accept you, darling. I know we said no more secrets, but I completely understand why you waited to tell me this. It’s a very personal thing.” 

Kara pulled back, giving Lena a soft kiss before moving to rest her head back on Lena’s shoulder. “Thank you.”

“I do have a lot of questions though.” Lena said, a slight mischievous tone to her voice. 

Kara let out a dramatic groan, sending the both of them into a fit of laughs. 

.  
.

It had been a week since Kara had told Lena about her Kryptonian biology and the alien had never felt better. Finally having someone who knew her, the real her, meant more than anyone could imagine. 

Kara had just finished dropping off two robbers she caught at the police department and was on her way to Lena’s penthouse for dinner. Dinner together had become a regular occurrence for the couple. It was Kara’s favorite time after a busy day, getting to unwind and spend time with her girlfriend. 

“You know that door’s not an entrance right?” Lena huffed out a laugh as Kara flew in through the balcony doors. 

“Yeah yeah, but it’s so convenient.” Kara wraps her arms around Lena, who was standing at the kitchen counter separating out boxes of Chinese food. 

Kara took a deep breath, inhaling Lena’s perfume as well as the smell of the food, “Mmm potstickers, I love you.” 

“Okay charmer, you can butter me up all you want but we’re not watching a Disney movie tonight.” 

“Aw but Lena, we still haven’t watched Mulan.” 

“No Disney.” Lena stated with one of her signature glares as she passed Kara’s numerous boxes of food to her.  
.  
.

After their dinner had been cleared out, and both of them changed into their pajamas, Lena put on a documentary about a specific physics discovery. Kara hadn’t been paying attention though, too busy observing Lena. 

“Is there a reason you’re staring at me?” Lena quirks her eyebrow, turning to look at Kara. 

“You’re beautiful.” The alien breathed out, shifting to pull Lena into a languid kiss. 

Lena brought her hand up to the back of Kara’s neck, deepening the kiss. Kara shifted Lena gently so that she was laying on the couch, Kara settling on top of her. 

The blonde lightly nipped at Lena’s bottom lip before moving to kiss down her jaw. Kara ran her hand up Lena’s side, bringing it around to gently cup her breast. Lena let out a low moan, spurring Kara on further. 

Lena slipped her hands under Kara’s shirt to drag her nails down Kara’s back. The pressure causes Kara to buck her hips into Lena’s, her bulge noticeable to Lena for the first time in their relationship. 

This discovery had Lena’s heart speeding up. The air shifted into something heavier as Kara pushed Lena’s shirt up and off of her. 

Lena reciprocated the move, pulling Karas shirt off and splaying her hand across her abs, relishing in her girlfriend's muscles. 

Kara moved further down, kissing the tops of Lena’s breasts. The blonde helped Lena raise slightly, unhooking her bra and flinging it off to the side. Kara quickly swiped a thumb over Lena’s nipple, causing the CEO to moan and drop her head back down. 

Lena bucked her hips up into Kara’s, searching for friction to give her a release. Her hips made contact with Kara’s now fully hard member. Gasping at the feeling of the contact through their clothing Lena bucked again. 

Kara ground her hips down meeting Lena’s motions as she brought one of the brunette’s nipples into her mouth. 

Lena let out a high pitched whine as Kara flicked her nipple with her tongue, her hand taking care of the other breast. 

Kara kept up her movement with her hips as she focused all her attention on Lena’s breasts. She always has been a boob girl. 

To Lena’s surprise, the grinding of Kara’s hips got faster, and her breathing more erratic, her focus on Lena’s breasts slipping slightly. 

Lena drug her nails down Kara’s back again, and suddenly Kara stiffened, her breath hitching. Her hips gave a few short thrusts as Kara let out a breathy moan. Kara’s head slumped down into Lena’s shoulder as she let out a few shuddering breaths. 

Lena gently rubbed her hand up to Kara’s neck, playing with the baby hairs there. “Darling, did you just come?” 

Kara nodded, keeping her head tucked into Lena’s shoulder as she worked to catch her breath. Lena hummed, continuing to play with the blonde’s hair. “You like my boobs that much, huh?” 

Kara let out a groan, “Lenaaa, your boobs are amazing but I’m so embarrassed right now.” She whined as she lifted her head up to awkwardly look down at Lena. 

“Don’t be embarrassed, it happens.” Lena smiles pulling Kara down into a passionate kiss. 

“Yeah it happens to horny teens, not Supergirl.” Kara mumbles as she sits up, looking down at the wet spot in her lap. 

Lena also looks down at Kara’s lap, taking in the substantial wet stain and the softer yet still noticeable bulge. Biting her lip, Lena grabbed Kara’s hand. 

“Hey, don’t worry about it Kara. This gives us a chance to work on your stamina.”

Kara grinned, liking the sound of getting more ‘stamina’ practice with Lena. 

“Come on, I’ll get you some new pants and you can go shower, clean yourself up. I’ll be waiting in bed for you.” 

Kara smiles, leaning in to kiss Lena before scooping her up into her arms and carrying her into the bedroom, depositing her on to the plush bed. 

“I’ll be fast!” Kara quips as she speeds into the bathroom, leaving a chuckling Lena on the bed. 

Lena leans back into the pillows and smiles, _I love that dork._


	2. Chapter 2

**Notes for the Chapter:**

> me: a lesbian virgin
> 
> also me: makes my first posted fic a smutty mess with a/b/o elements

By the time Kara had finished up in the shower, Lena was already asleep. Kara smiled softly at the view of her girlfriend, sleeping peacefully after a long day at work. The blonde quickly slipped into the pajamas Lena had provided her, a loose shirt that was originally Kara’s and a baggy pair of sweatpants. 

Kara slipped into the bed, wrapping an arm around Lena’s stomach. Lena took a deep breath and turned over in Kara’s arms, nuzzling her face into the blinde’s chest. 

“Love you.” The CEO mumbled. 

“I love you too.” Kara responded, a sleepy smile spreading across her face as she settled around Lena, letting sleep overtake her. 

.  
.

Lena slowly blinked awake, the sun not having risen yet. Furrowing her brows she wondered why she was awake so early on her day off. She quickly got her answer when she felt movement behind her. 

“Lena…” the Kryptonian breathed out in her sleep. 

Lena tensed when she felt a noticeable hardness pressed against her backside, before smirking when she realized just what kind of dream Kara was having. 

Kara moaned lightly, the movement of her hips becoming more deliberate. The hand wrapped around Lena’s stomach tightened its hold on the brunette’s shirt. 

Lena reached her hand back, brushing her fingers through blonde locks. “Kara, wake up.” 

“Mmm…” 

“Kara, darling, wake up.”

“Lena?” The blonde sniffed, lifting her head and blinking blearily. “It’s early, you okay?” 

Lena twisted around to face Kara. “Yeah everything’s perfect, are you okay?” She asked with a pointed eyebrow raise and a glance down in between them. 

Kara took stock of the situation before blushing furiously. “I- I am so sorry Lena, I didn’t mean to-“ 

“Take off your pants.” Lena interrupted. 

“-what?” 

“Take your pants off. Only if you want to of course! I just thought I could help you out with your uh...situation.” 

“I want to! I just- are you sure?” 

“Yes I’m sure.” Lena smiled, leaning in to give Kara a languid kiss. Kara deepened the kiss, pushing Lena down so the Kryptonian was on top of her. 

Kara’s hand slid across Lena’s side, brushing the skin that had been exposed from her sleep shirt riding up.

“I wanna take care of you.” Kara said in between kisses she placed on Lena’s neck. “Is that okay?” 

“Yes.” Lena breathed out as Kara trailed her hand down across Lena’s hip, letting her fingertips slide under the band of her sleep shorts. 

Lena quickly sat up, pulling her shirt off and tossing it to the side. Now topless, as she doesn’t wear a bra to bed, she settled back down, pulling Kara by the neck to bring her back in for a heady kiss. 

“You’re so beautiful.” Kara said as she pulled away to lean down and take one of Lena’s nipples into her mouth. The brunette let out a moan, her hand tightening in Kara’s hair. 

Lena placed her unoccupied hand on top of the hand Kara had on her waist, “Touch me.” 

With that encouragement, Kara slid her hand down into Lena’s pants, realizing she decided to forego panties. Kara’s fingers met a soft patch of hair and then soft warm wetness. 

Both women let out moans as Kara reaches Lena’s sensitive folds. Kara lets her fingers dip down, gathering the wetness that has formed.

“You’re so wet.” Kara groaned, leaving hot kisses across Lena’s breasts. 

Lena was about to respond but was cut off with a gasp of pleasure as Kara’s fingers circled her clit. 

Kara could hear Lena’s heartbeat speed up as the brunette let out a breathy moan, “Inside. Want your fingers in me.” 

Kara followed Lena’s requests, slowly pushing her middle finger into Lena. Kara slowly thrust her finger in and out before adding her index finger as well. Continuing her slow pace, Kara brought her lips back to Lena’s nipple. 

Lena gasped, “Faster!” 

Kara smirked, thrusting into her faster with her fingers, making sure the heel of her hand was applying pressure to Lena’s clit. Kara could feel the fluttering of Lena’s walls around her fingers, knowing the brunette was getting close. 

Lena’s moans got higher in pitch as she got closer to release. Kara’s Kryptonian alpha instincts suddenly kicked in, giving her a strong desire to bite and claim Lena as her mate. Kara quickly shook that thought, _the mating conversation will be for another day_ , and settled on lightly nipping at Lena’s neck, sure to leave a slight mark. 

“Kara!” Lena moaned out as her walls clenched tightly around the alien’s fingers. The brunette’s body tensed up and her breathing stuttered as Kara continued to move her fingers, prolonging Lena’s climax. 

Lena let out a deep breath as her climax finally tapered off and Kara removed her fingers, settling her hand on Lena’s hip. Kara peppered kisses across Lena’s face as Lena caught her breath, a blissed out expression overtaking her features. 

Lena took Kara’s hand from her hip, bringing the two fingers up and into her mouth. She sucked on the alpha’s fingers, her tongue swirling to clean them of her essence. 

Kara’s mouth gaped open at the feeling and visual of what Lena just did. Her cock gave a heavy throb, bringing Kara’s attention to the fact the she was leaking pre-come, dirtying another pair of pants as she also didn’t put underwear on the night before. 

Lena removed Kara’s fingers from her mouth with a soft pop before placing light kisses across her fingertips. Lena nudged at Kara, finally reaching to take the alien’s shirt off. 

Once Kara’s shirt was removed, Lena took a moment to take in the sight of her girlfriend; blonde hair disheveled, lips swollen, pupils dilated, abs clenching, and most noticeable of all a prominent bulge with a wet spot to top it off. 

“Let me take care of you now.” Lena said sliding her hands across Kara’s chest, thumbing at her nipples before lightly scratching at her abs. 

“Are you sure? I probably won’t last long..” 

“Darling, I’ve been wanting to do this longer than you can imagine.” Lena assured, letting her hands play with the waistband of Kara’s sweats. 

“Okay, yes.. l- please” Kara stammered out as Lena’s fingers dipped slightly under the waistband, rubbing over her hip bones and at the top of a patch of trimmed hair. 

Lena hooked her fingers and tugged, Kara lifting slightly so her pants could be removed fully. Lena’s eyes widened at the sight that greeted her. Kara, goofy loveable and sometimes awkward Kara, had the body and dick of a god.

Kara’s cock was standing at attention, the tip an angry red and leaking with pre-come. Lena swears she can see her throbbing with how hard she is. Her length reached up to her bellybutton and Lena knew she’d have to adjust to the girth. 

“Fuck…” Lena whispered out, biting her lip at the sight. 

“Is something wrong?” Kara asked worriedly, knowing that her body must be a lot to take in for a human. 

“You’re perfect.” Lena said, pulling Kara in for a searing kiss. Kara deepened the kiss pulling Lena in closer to her. Lena dug her nails into the Kryptonian’s abs before trailing her fingers downwards. 

Lena trailed kisses down Kara’s neck, nipping lightly here and there. Lena lifted up to give a kiss to Kara’s lips right as she let her fingers reach and wrap around the base of Kara’s cock. 

Kara gasped at the new sensation and tensed slightly. _Okay Kara, you got this_

“Relax” Lena whispered into her ear, nipping at her lobe and trailing more kisses across her jaw. 

Lena began to move her hand up Kara’s length as she felt the alien relax as she got used to the feeling. 

_One stroke, wow, this feels amazing, okay Kara, you got this, you’re an alpha..._

_...two…_

_...three…_

_-shit-_

_...four…_

_-fuck-_

_...five._

“Ah!” Kara cried out as Lena stroked her cock for the fifth time, her body tensing as she came. Her cum spurting out onto her stomach and chest and spilling down across Lena’s hand. 

Lena slowly stroked up and down Kara’s length a few more times, milking the rest of the cum Kara had to give. Once the drops of cum had tapered off, Lena released Kara’s dick, turning her attention up to Kara’s face. 

The alien was taking deep breaths, staring down at Lena with a dopey grin on her face and with a blush spreading across her cheeks. “I love you. That was amazing and also embarrassing.” 

“I love you too, and don’t be embarrassed that was quite possibly the hottest thing I’ve ever witnessed.” 

“Even though I only lasted like...30 seconds, if that?” Kara asked, as she got up to clean herself off, a joking tone to her voice but also some insecurity underneath the jest. 

“Trust me Kara, we’ll work on it and it can only get better from here.” 

Kara walked back into the bedroom with a smile, holding a damp washcloth so that she could help clean Lena, as well as switch out the sheets. 

“Well...if working on it means more of that, when can we start?” Kara laughed out, an exaggerated waggle of her eyebrows as she wrapped Lena back up in her arms. 

Lena let out a snort, snuggling deeper into the blanket and Kara’s arms, “After the sun comes up, it’s my day off.” 

Kara giggled, pressing a kiss Lena’s forehead, “I love you.”

“I love you too.”

**Notes for the Chapter:**

> Wowowowowow! 200+ kudos and 12 comments! I can’t thank you all enough for reading and liking this attempt at a fic. 
> 
> I’m gonna be honest, this all started as a random idea I had and it’s not planned out at all. 
> 
> I know my writing style isn’t the best or anything, and if you notice any glaring mistakes let me know. This fic is also letting me stretch my writing legs after a long time so pls forgive me for any choppiness or tense changes. :) 
> 
> Tell me what ya think of this update and if you have any suggestions let me know!

**Author's Note:**

> I think I’m gonna continue this if I get some more inspiration.


End file.
